Gu Qiang For the project team FEL progress in SINAP Gu Qiang For the project team

Outline The experiments at SDUV-FEL The status of the Soft X-ray FEL Facility The progress of the Hard X-ray FEL Facility base on X band technology

The experiments at SDUV-FEL 2009.04: Linac commissioning 2009.09: SASE lasing 2010.05: Seeding signal 2010.05: Echo signal (`double-peak’) 2010.12: HGHG saturation 2011.04: EEHG-FEL lasing 2011.12: HGHG continuous tunability 2012.04: Cascaded HGHG 2013.08: EEHG@10th harmonic 2013.11: Crossed-planar undulators for polarization control 2014.04: Corrugated device operation in a FEL 2014.12: CPA of CHG (in preparation)

New FEL experiment layout Since 24th July, 2013

Scheme of Echo-10 Beam: 165-175MeV, ~200 pC, 3~8ps Seed laser 1: 523 nm, 8.7 ps (FWHM), 60 J Seed laser 2: 2500 nm, ~100 fs (FWHM), 40 J Radiator: 40mm*80 periods, with variable gap. Output wavelength: 800 nm-200nm. The echo signal occurs at the wave number: kEEHG=nk1+mk2, n and m are integers.

Echo-10 data The central wavelength of HGHG and EEHG will be different because wavelengths of two seed lasers are different:

Polarization control with crossed-planar undulators K. J. Kim, Y. Ding, Z. Huang, Y. H. Li, B. Faatz, W. Decking, H. Geng et al Arbitrary Polarization state > kHz Polarization switch rate High Polarization degree

Modulator (EMU65) Period Length [m] 0.065 Undulator Peak Field [Gs] ~ 2700 Period Number 10 Undulator Parameter ~ 1.16 Crossed Planar Undulators 0.05 10000 ~ 2100 ~ 0.68 Seed Laser System Wavelength [nm] 1047 Time Duration (FWHM) [ps] ~ 8.0 Peak Power [MW] ~ 10 Rayleigh Length [m] ~ 3.0 Phase Shifter Total Length [m] ~ 0.4 Shift Range 0 ~ 2π T. Zhang, H. X. Deng*, J. H. Chen et al., Nucl. Instr. and Meth. A 680, 112 (2012)

H. X. Deng, T. Zhang, L. Feng et al. , Phys. Rev. ST Accel H. X. Deng, T. Zhang, L. Feng et al., Phys. Rev. ST Accel. Beams 17, 020704 (2014).

Corrugated structure for beam linearizer Material Aluminum depth δ 2.0mm corrugated width g 0.3mm period p 0.6mm length 300mm width 30mm Q Gu, et. al., TUPB022, LINAC 2012

Blue：corrugated structure open, Red：corrugated structure closed (2mm separation) Central wavelength: 8nm redshift, FEL bandwidth: 7.34nm  3.75nm H. X. Deng, M. Zhang, C. Feng et al., Phys. Rev. Lett 113 (2014)

Summary SDUV-FEL is one of the most competitive test FEL facilities, on which several FEL experiments have been accomplished recently. 10th harmonic of EEHG. First demonstration of polarization switching using crossed-planar undulators in a FEL facility. First corrugated beam linearizer operated in a FEL facility. CPA of CHG in preparation. The experiment results agree well with simulations, which confirms the corresponding theories for FEL improvement. New experiments are on the way.

Shanghai X-ray FEL 2014.12, Ground breaking 2015.12, Build ready 2016.2, Utilities ready 2016.6, Installation finished 2017.6, Lasing 2017.12, Acceptance

Layout and key parameters of SXFEL Nominal Upgrade Unit Output Wavelength 8.8nm 3 nm Output FEL Power  100 MW FEL pulse length 100 - 200 fs Bunch charge 0.5 nC Energy 0.84 1.2~1.3 GeV Energy spread <0.15% Normalized emittance 2.5 ~2.5 mm.mrad Pulse length (FWHM) 1.0 ps Peak current kA Rep. rate 10 Hz

Summary The ground breaking of the SXFEL facility was hold on 30th Dec., 2014. Lasing should be achieved in 2017. The progress of the key technology and components inspired the confidence in construction and commissioning. The facility could be a user facility at 3nm with minor upgrade in future.

Hard X-ray FEL based on X band technology We joined the R&D of the CLIC-FEL collaboration and the X band technology collaboration. We hope to propose a compact hard X-ray FEL base on X band technology for the future light source in China.

Tolerance budget study tols.err = [ 0.05 % inj_arr ps 2 % inj_dQ % 0.05 % L1_pha deg 0.02 % L1_volt % 0.05 % Lx_pha deg 0.02 % Lx_volt % 0.05 % L2_pha deg 0.02 % L2_volt % 0.05 % L3_pha deg 0.02 % L3_volt % 0.001 % BC1_dR56 0.001 % BC2_dR56 ]; dE(0.02%) dI(10%) dt(20fs) inj_arr 0.22294 0.259383 0.087965 inj_dQ 0.338978 0.598442 0.201874 L1_pha 0.30541 0.621765 0.700465 L1_volt 0.253763 0.142405 0.468724 Lx_pha 0.050167 0.526496 0.01209 Lx_volt 0.04418 0.014999 0.083152 L2_pha 0.313746 0.077781 0.141824 L2_volt 0.311427 0.010803 0.143098 L3_pha 0.118905 1.58E-05 L3_volt 0.134476 6.33E-06 BC1_dR56 0.020209 0.010617 0.026692 BC2_dR56 0.005807 0.000612 -0.00931 total 0.744873 1.056402 0.898496

Preliminary design of the linac 18MV/m 0deg 39.7MV/m 180deg 100MV/m 30deg 25MV/m -18.4deg -60mm 80MV/m -7.2deg -11mm 80MV/m, 10deg 1.5m, 0.005GeV 0.1% 25A 17m, 0.132GeV 0.13% 42m, 0.521GeV 1.38% 54m, 0.521GeV 1.38% 500A 92m, 2.01GeV 0.347% 105m, 2.01GeV 0.347% 3000A 175m, 6GeV 0.009% 3000A Gun L0(s) L1(s) X BC1 L2(x) BC2 L3(x) RF-Gun S-band L0 L1 L2 X-band L3 Lx unit No. of RF sect. 1 2 6 10 28 frequency 2.856 11.424 GHz Kly. power 50 80 MW TWS/kly. Gradient 120 18 25 40 MV/m SLED No Yes

Consideration on undulators Period Gap U1 30mm 10~30 mm U2 14mm 2~10 mm U3 10mm

SASE with 6.4 GeV (U3, with tapering)

Summary 1D tracking and the tolerance budget have been studied. The baseline of the linac has been established and 6D tracking has been done. Study on the FEL radiator started and the first S2E simulation has been done. Optimization of the linac and FEL radiator should be studied in the future.